Field of the Invention
Embodiments of the present invention are directed to a wireless power transfer system. More specifically, embodiments of the present invention are directed to systems and methods for wirelessly transmitting power via helical antennas using near-field electromagnetic transmissions.
Description of the Prior Art
Given the prevalence of electrically-powered devices, a significant hurdle to the widespread use of such devices is the ability to provide electrical power on demand. Typically, electrically-powered devices will include energy storage devices, such as batteries, for providing power to the devices. Nevertheless, batteries will lose their charge over time, thus, making the devices inoperable until the batteries can be recharged. The requirement for charging a battery is itself problematic, as standard charging processes generally require a hard-wire connection between the battery and a charging source (e.g., power-grid, generator, alternator, etc.). Such hard-wire connections require consideration of the extensive costs of materials (e.g., power cables, connectors, etc.), the weight of materials, and the space required for placement of the materials.
Numerous studies have been conducted in attempts to wirelessly transfer power between electromagnetically-coupled antennas. Most studies have focused on transferring power through use of far-field radiation (i.e., plane-wave radiation). In particular, a transmitting antenna will transmit far-field radiation to a receiving antenna that collects the radiation to use as electrical power. However, such fair-field radiation transmissions suffer from the significant problem of the radiation's strength and/or magnitude reducing exponentially with distance. Such a reduction in radiation strength significantly affects the efficiencies of such wireless power transfer methods.
Thus, what is needed is a way to transmit electrical power wirelessly, so as to avoid the need for hard-wire connections between electrically-powered devices and power sources. Furthermore, what is needed is a way to transmit electrical power wirelessly in a manner than maintains sufficient efficiency so as to make wireless transfer of power practically and economically feasible.